• Journal of Yeungnam Medical Science
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• v.18 no.1
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• pp.13-29
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• 2001

The enzyme activities of creatine kinase (CK), its isoenzyme MB (CK-MB) and of lactate dehydrogenase isoenzyme 1 (LD-1) have been used for years in diagnosing patients with chest pain in order to differentiate patients with acute myocardial infarction (AMI) from non-AMI patients. These methods are easy to perform as automated analyses, but they are not specific for cardiac muscle damage. During the early 90's the situation changed. First, creatine kinase ME mass (CK-MB mass) replaced the measurement of CK-MB activity. Subsequently cardiac-specific proteins, troponin T (cTnT) and troponin I (cTnI) appeared and displacing LD-1 analysis. However, troponin concentrations in blood increase only from four to six hours after onset of chest pain. Therefore a rapid marker such as myoglobin, fatty acid binding protein or glycogen phosphorylase BB could be used in early diagnosis of AMI. On the other hand, CK-MB isoforms alone may also be useful in rapid diagnosis of cardiac muscle damage. Myoglobin, CK-MB mass, cTnT and cTnI are nowadays widely used in diagnosing patients with acute chest pain. Myoglobin is not cardiac-specific and therefore requires supplementation with some other analyses such as troponins to support the myoglobin value. Troponins are very highly cardiac-specific. Only the sera of some patients with severe renal failure, which requires hemodialysis, have elevated cTnT and/or cTnI without there being any evidence of cardiac damage. The latest studies have shown that elevated troponin levels in sera of hemodialysis patients point to an increased risk of future cardiac events in a similar manner to the elevated troponin values in sera of patients with unstable angina pectoris. In addition, the bedside tests for cTnT and cTnI alone- or together with myoglobin and CK-ME mass can be used instead of quantitative analyses in the diagnosis of patients with chest pain. These rapid tests are easy to perform and they do not require expensive instrumentation. For the diagnosis of patient with chest pain, routinely myoglobin and CK-ME mass measurements should be performed whenever they are requested (24 h/day) and cTnT or cTnI on admission to the hospital and then 4-6 and 12 hours later and maintained less than 10% in imprecision.

• BMB Reports
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• v.54 no.9
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• pp.464-469
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• 2021

Cardiomyocyte differentiation occurs through complex and finely regulated processes including cardiac lineage commitment and maturation from pluripotent stem cells (PSCs). To gain some insight into the genome-wide characteristics of cardiac lineage commitment, we performed transcriptome analysis on both mouse embryonic stem cells (mESCs) and human induced PSCs (hiPSCs) at specific stages of cardiomyocyte differentiation. Specifically, the gene expression profiles and the protein-protein interaction networks of the mESC-derived platelet-derived growth factor receptor-alpha (PDGFRα)⁺ cardiac lineage-committed cells (CLCs) and hiPSC-derived kinase insert domain receptor (KDR)⁺ and PDGFRα⁺ cardiac progenitor cells (CPCs) at cardiac lineage commitment were compared with those of mesodermal cells and differentiated cardiomyocytes. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses revealed that the genes significantly upregulated at cardiac lineage commitment were associated with responses to organic substances and external stimuli, extracellular and myocardial contractile components, receptor binding, gated channel activity, PI3K-AKT signaling, and cardiac hypertrophy and dilation pathways. Protein-protein interaction network analysis revealed that the expression levels of genes that regulate cardiac maturation, heart contraction, and calcium handling showed a consistent increase during cardiac differentiation; however, the expression levels of genes that regulate cell differentiation and multicellular organism development decreased at the cardiac maturation stage following lineage commitment. Additionally, we identified for the first time the protein-protein interaction network connecting cardiac development, the immune system, and metabolism during cardiac lineage commitment in both mESC-derived PDGFRα⁺ CLCs and hiPSC-derived KDR⁺PDGFRα⁺ CPCs. These findings shed light on the regulation of cardiac lineage commitment and the pathogenesis of cardiometabolic diseases.

• International journal of advanced smart convergence
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• v.13 no.2
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• pp.187-194
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• 2024

For precise cardiac diagnostics and treatment, we introduce a novel method for patient-specific mapping between myocardial and coronary anatomy, leveraging local variations in myocardial thickness. This complex system integrates and automates multiple sophisticated components, including left ventricle segmentation, myocardium segmentation, long-axis estimation, coronary artery tracking, and advanced geodesic Voronoi distance mapping. It meticulously accounts for variations in myocardial thickness and precisely delineates the boundaries between coronary territories according to the conventional 17-segment myocardial model. Each phase of the system provides a step-by-step approach to automate coronary artery mapping onto the myocardium. This innovative method promises to transform cardiac imaging by offering highly precise, automated, and patient-specific analyses, potentially enhancing the accuracy of diagnoses and the effectiveness of therapeutic interventions for various cardiac conditions.

• Reproductive and Developmental Biology
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• v.30 no.1
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• pp.47-52
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• 2006

This study was conducted to examine whether the parthenogenetic mouse embryonic stem (P-mES) cells can differentiate into functional cardiomyocytes in vitro similar to (mES) cells. p-mES04 and IVF-derived mES03 cells were cultured by suspension culture for 4 days. The formed embryoid bodies (EBs) were treated with 0.75% dimethyl-sulfoxide (DMSO) for further 4 days (4-/4+), and then plated onto gelatin coated culture dish. The appearance of contracting cardiomyocytes from the P-mES04 and mES03 cells was examined for 30 days. The highest cumulative frequency was detected at days 13 (69.83%) and 22 (61.3%), respectively. By immunocytochemistry, beating P-mES04 cells were positively stained with muscle specific anti-sarcomeric a-actinin Ab and cardiac specific anti-cardiac troponin I Ab similar to contracted mES03 cells. When the expression of cardiac muscle-specific genes was analyzed by RT-PCR, beating P-mES04 cells were expressed cardiac specific L-type calcium channel, a1C, cardiac myosin heavy chain a, cardiac muscle heavy polypeptide $7{\beta}$, GATA binding protein 4 and atrial natriuretic factor, but not expressed skeletal muscle specific L-type calcium channel, a1S, which was similar to male adult heart cells and mES03-derived beating cardiomyocytes. The result demonstrates that the P-mES cells can be used as an alternative for the study on the characteristic analysis of in vitro cardiomyocyte differentiation from the ES cells.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.10a
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• pp.100-100
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• 2003

Pluripotent embryonic stem (ES) cells differentiate spontaneously into beating cardiomyocytes via embryo-like aggregates. We describe the use of mouse embryonic stem (mES03) cells as a reproducible differentiation system for cardiomyocyte. To induce cardiomyocytic differentiation, mES03 cells were dissociated and allowed to aggregate (EB formation) at the presence of 0 75% dimethyl sulfoxide (DMSO) for 4 days and then another 4 days without DMSO (4+/4-). Thus treated EBs were plated onto gelatin-coated dish for differentiation. Spontaneously contracting colonies which appeared in approximately 4-5 days upon differentiation. Expression of cardiac-specific genes were determined by RT-PCR. Rebust expression of myosin light chain (MLC-2V), cardiac myosin heavy chain $\alpha$, cardiac muscle heavy polypeptide 7 $\beta(\beta$-MHC), cardiac transcription factor GATA4 and skeletal muscle-specific ${\alpha}_1$-subunit of the L-type calcium channel (${\alpha}_1 CaCh_{sm}$) were detected as early as 8 days after EB formation, but message of cardiac muscle-specific $\alpha$$_1$-subunit of the L-type calcium channel (${\alpha}_1$CaCh) were revealed at a low level. Strikingly, the expression of atrial natriuretic factor (ANF) was not detected. When spontaneous contracting cell masses were examined their electrophysiological features by patch-clamp technique, it showed ventricle-like action potential 17 days after the EB formation. This study indicates that mES03 cell-derived cardiomyocytes displayed biochemical and electrophysiological properties of cardiomyocytes and DMSO enhanced development of cardiomyocytes in 4+/4- method.

• Journal of Chest Surgery
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• v.56 no.2
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• pp.136-139
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• 2023

Although cardiac myxoma is one of the most common types of benign cardiac tumors, infected cardiac myxoma is very infrequent. The diagnosis of infected cardiac myxoma may be challenging because the presenting symptoms are non-specific and established management guidelines are lacking. This report describes a 39-year-old woman with a 5-month history of uncontrolled fever, chills, and myalgia who was diagnosed with myxoma and underwent mass excision. Although blood and urine cultures were negative for growing bacteria, a pathologic examination showed that the excised mass was a left atrial myxoma, with pan-bacterial polymerase chain reaction (PCR) of the surgical specimen revealing Haemophilus parainfluenzae at 99.87%, resulting in a diagnosis of infected cardiac myxoma. Laboratory tests, such as PCR, may supplement culture results in the diagnosis of infected cardiac myxoma.

• The Korean Journal of Physiology and Pharmacology
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• v.28 no.3
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• pp.285-294
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• 2024

Myocardial infarction is one of the leading causes of mortality globally. Currently, the pleiotropic inflammatory cytokine interleukin-6 (IL-6) is considered to be intimately related to the severity of myocardial injury during myocardial infarction. Interventions targeting IL-6 are a promising therapeutic option for myocardial infarction, but the underlying molecular mechanisms are not well understood. Here, we report the novel role of IL-6 in regulating adverse cardiac remodeling mediated by fibroblasts in a mouse model of myocardial infarction. It was found that the elevated expression of IL-6 in myocardium and cardiac fibroblasts was observed after myocardial infarction. Further, fibroblast-specific knockdown of Il6 significantly attenuated cardiac fibrosis and adverse cardiac remodeling and preserved cardiac function induced by myocardial infarction. Mechanistically, the role of Il6 contributing to cardiac fibrosis depends on signal transduction and activation of transcription (STAT)3 signaling activation. Additionally, Stat3 binds to the Il11 promoter region and contributes to the increased expression of Il11, which exacerbates cardiac fibrosis. In conclusion, these results suggest a novel role for IL-6 derived from fibroblasts in mediating Stat3 activation and substantially augmented Il11 expression in promoting cardiac fibrosis, highlighting its potential as a therapeutic target for cardiac fibrosis.

• Proceedings of the KSAR Conference
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• 2003.06a
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• pp.76-76
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• 2003

Pluripotent embryonic stem cells can differentiate into beating cardiomyocytes with proper culture conditions and stimulants via embryo-like aggregates. We describe here the use of mouse embryonic stem (mES03) cells as a reproducible differentiation system for cardiomyocyte. mES03 cells growing in colonies were dissociated and allowed to re-aggregated in suspension [embryoid body (EB) formation〕. To induce cardiomyocytic differentiation, cells were exposed to 0.75% dimethyl sulfoxide (DMSO) during EB formation for 4 days and then another 4 days without DMSO (4+/4-). Thus treated EB was plated onto gelatin-coated dishes for differentiation. Spontaneously contracting colonies which appeared in approximately 4~5 days upon differentiation were mechanically dissected, enzymatically dispersed, plated onto coverslips, and then incubated for another 48~72 hrs. By RT-PCR, robust expression of cardiac myosin heavy chain $\alpha$, cardiac muscle heavy polypeptide 7 $\beta$($\beta$-MHC), cardiac transcription factor GATA4, and skeletal muscle-specific $\alpha$$_1$-subunit of the L-type calcium channel ($\alpha$$_1$CaC $h_{sm}$ ) were detected as early as 8 days after EB formation, but message of cardiac muscle-specific $\alpha$$_1$-subunit of the L-type calcium channel ($\alpha$$_1$CaCh) were reveled at a low level. In contrast, expression of myosin light chain (MLC-2V) and atrial natriuretic factor (ANF) were not detected during EB formation for 8 days. However, a strong expression of the atrial-specific ANF gene was expressed from day 8 onward, which were remained constant in EB. (cardiac specialization and terminal differentiation stage). Electrophysiological examination of spontaneously contracting cells showed ventricle-like action potential 17 days after the EB formation. This study indicates that mES03 cell-derived cardiomyocytes via 4+/4- protocol displayed biochemical and electrophysiological properties of subpopulation of cardiomyocytes.

• Journal of Chest Surgery
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• v.48 no.5
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• pp.311-317
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• 2015

Background: Robotic surgery is an alternative to minimally invasive surgery. The aim of this study was to report on current trends in robotic thoracic and cardiovascular surgical techniques in Korea. Methods: Data from the National Evidence-based Healthcare Collaborating Agency (NECA) between January 2006 and June 2012 were used in this study, including a total of 932 cases of robotic surgeries reported to NECA. The annual trends in the case volume, indications for robotic surgery, and distribution by hospitals and surgeons were analyzed in this study. Results: Of the 932 cases, 591 (63%) were thoracic operations and 340 (37%) were cardiac operations. The case number increased explosively in 2007 and 2008. However, the rate of increase regained a steady state after 2011. The main indications for robotic thoracic surgery were pulmonary disease (n=271, 46%), esophageal disease (n=199, 34%), and mediastinal disease (n=117, 20%). The main indications for robotic cardiac surgery were valvular heart disease (n=228, 67%), atrial septal defect (n=79, 23%), and cardiac myxoma (n=27, 8%). Robotic thoracic and cardiovascular surgeries were performed in 19 hospitals. Three large volume hospitals performed 94% of the case volume of robotic cardiac surgery and 74% of robotic thoracic surgery. Centralization of robotic operation was significantly (p<0.0001) more common in cardiac surgery than in thoracic surgery. A total of 39 surgeons performed robotic surgeries. However, only 27% of cardiac surgeons and 23% of thoracic surgeons performed more than 10 cases of robotic surgery. Conclusion: Trend analysis of robotic and cardiovascular operations demonstrated a gradual increase in the surgical volume in Korea. Meanwhile, centralization of surgical cases toward specific surgeons in specific hospitals was observed.

• The Korean Journal of Physiology and Pharmacology
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• v.26 no.5
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• pp.357-365
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• 2022

Simultaneous myofibril and mitochondrial development is crucial for the cardiac differentiation of pluripotent stem cells (PSCs). Specifically, mitochondrial energy metabolism (MEM) development in cardiomyocytes is essential for the beating function. Although previous studies have reported that MEM is correlated with cardiac differentiation, the process and timing of MEM regulation for cardiac differentiation remain poorly understood. Here, we performed transcriptome analysis of cells at specific stages of cardiac differentiation from mouse embryonic stem cells (mESCs) and human induced PSCs (hiPSCs). We selected MEM genes strongly upregulated at cardiac lineage commitment and in a time-dependent manner during cardiac maturation and identified the protein-protein interaction networks. Notably, MEM proteins were found to interact closely with cardiac maturation-related proteins rather than with cardiac lineage commitment-related proteins. Furthermore, MEM proteins were found to primarily interact with cardiac muscle contractile proteins rather than with cardiac transcription factors. We identified several candidate MEM regulatory genes involved in cardiac lineage commitment (Cck, Bdnf, Fabp4, Cebpα, and Cdkn2a in mESC-derived cells, and CCK and NOS3 in hiPSC-derived cells) and cardiac maturation (Ppargc1α, Pgam2, Cox6a2, and Fabp3 in mESC-derived cells, and PGAM2 and SLC25A4 in hiPSC-derived cells). Therefore, our findings show the importance of MEM in cardiac maturation.